How wide is the Panasonic 14mm prime lens?

I compared my Panasonic 14mm f/2.5 lens on E-M5 to a Sigma 19mm f/2.8 lens on NEX-C3 and found that the former was significantly wider than the latter. I also compared Panasonic 14mm prime to the 14mm end of the Panasonic 14-45mm zoom and found the former to be again significantly wider than the latter.

Is the Pana 14 more really wider than 28mm equivalent or are those other lenses really less wide than 28mm equivalent? Has anyone compared the Pana 14/2.5 to 28mm equivalent lenses from other systems?

Interesting... I have a 14-140 and 12-35 I can try and test the 14mm against to see if there's an appreciable difference @ 14mm. If it turns out to be actually wider than 28mm equivalent that just makes the 14mm that much more of a bargain for wide angle fans! :smile:

EDIT: forgot, I've got the 9-18 and 7-14 I can also test. Will have to wait until tonight but I'll try and do a tripod-mounted test.

There should be a difference between the 14mm on m4/3 and the 19mm on APS NEX. The 14mm m4/3 at a 2x crop factor would be a 28mm but the 19mm on a 1.5x crop factor would be a 28.5mm. The specs I found on B&H give 75 degrees angle for the 14mm and 73.5 degrees for the 19mm.

There shouldn't be much of a difference between different 14mm lenses on m4/3 however{not visibly different at least}. If there is than something isn't quite right. It might be the rounding of numbers? Perhaps the kit lenses are rounded down from a 14.5mm and the 14mm Pany lens is a true 14 or even a 13.8 rounded up?

Only thing I could think is maybe the lens correction on the older 14 is not cropping out as much for the final image and some of the other lens have much more optical distortion that then needs to be cropped out ?

Might be interesting to take some raws then open in a program like C1 that does not correct the M4/3 lens and see whats up ?

I know with my 12-35 its interesting to see how much gets cropped out

I do like the corrections but wish it was done as a choice but understand why its not

Amin, as I understand it, zooms tend to cheat at both ends, while being relatively accurate in the middle. It's entirely possible that the 14-45 is actually closer to 15mm than to 14mm.

It may also depend on your focusing distance as well. At closer focusing distances, the 14mm may be wider than it's "supposed to be." It might be worth comparing the two lenses at infinity to determine which is wider.

Because of the massive distortion being corrected, Lenstip was concerned that the 14mm after in-body correction was closer to a 15.5mm. They then tested the angle of view explicitly using star charts and determined that before the automatic corrections the camera does, the 14mm is actually closer to 13mm than to 14mm...though you'll only see 13mm AOV in a RAW converter that doesn't read the metadata. The corrected image that we see in JPEGs or in Lightroom is exactly where it's supposed to be: 75.1 degrees (that is, "exactly" when the margin of error is taken into account).

Very interesting, I had no idea the distortion correction included cropping in the image a bit at the edges?

I still need to do a tripod test but a handheld quick n dirty test seemed to indicate that if anything, the 14mm pancake was about the same or narrower than my 14-140mm. Actually the 7-14mm seemed the widest at the 14mm setting out of the 14mm, 14-140mm, 9-18mm, 12-35mm and 7-14mm I tested.

the degree of field of view of a lens can be very different at given focal length. We just don't commonly think of lens design and it's effect. It's reasonable to expect what the general FoV is at a given FL because it's generally within 5-8 degrees across diferent designs at the wide end. For an extreme example, think of the 8mm fisheye at 180 degrees and the 7mm rectilinear at 117 degrees.

There should be a difference between the 14mm on m4/3 and the 19mm on APS NEX. The 14mm m4/3 at a 2x crop factor would be a 28mm but the 19mm on a 1.5x crop factor would be a 28.5mm... There shouldn't be much of a difference between different 14mm lenses on m4/3 however...

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There are plenty of lenses for all different formats which are given a nominal focal length which is different than actual. For example, the Sigma 50mm lens for Canon DSLRs is noticeably wider than the Canon 50mm lens for the same.

As far as distortion goes, the nominal focal length is supposed to correlate with the angle of view of the software-corrected image as rendered by the in-camera JPEG. The degree of distortion correction can vary slightly between different RAW processors. The actual focal length is thus shorter than indicated for each of our lenses that has significant barrel correction applied.

Thanks, that was helpful. I knew that it was supposed to work that way (angle of view corresponding to corrected image), but it's good to get confirmation that the Pana 14 is actually giving the 28mm equivalent angle of view. The Sigma 19 on NEX seemed quite a bit longer, so I think it's probably longer than 28.5-equivalent on that body. Likewise our kit zooms probably start at 14.5 or 15 rather than 14, just as you said.

The prime has a slightly greater FOV, probably because the zoom extends further out.

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14mm is 14mm is 14mm... More likely one, or both, are only nominally 14mm. You'd likely get similar results if you used 3 different 14mm primes or 3 different 7-14/4 zooms. Very few lenses come out of the factory at exactly their marked FL. Leica is the only manufacturer I remember marking actual FLs on lenses, and they may not do it any more, not sure. I've owned a lot of Leica lenses and I don't recall a single one that was marked exactly at its nominal FL. :smile: Most were a little shorter, some were longer, (shrug)

I put my OM-D on my tripod and compared 14mm shots from the 14/2.5, 7-14, and 12-50 - exact same scene, same f-stop (f/4.0). The 7-14 @ 14mm showed distinct pincushion distortion, noticeable vignette (no surprise, f/4 is wide open) and was a hair wider than the 14/2.5. The 12-50 @ 14mm was a hair wider than the 14/2.5 and had the brightest corners of the three. The 14/2.5 had the least distortion of the three.

They were all very, very close in angle-of-view. It's tough to say that I nailed 14mm on the zooms, despite what the exif says, so call them even.

Very interesting, I had no idea the distortion correction included cropping in the image a bit at the edges?

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It doesn't. The image is cropped before distortion correction is applied. When correction is applied, data from outside that crop can be brought into the frame.

I have noticed this while using the 14mm on the E-PL2. The Olympus software does not correct distortion automatically, but has settings to allow correction. I was concerned that the correction would lose information in the borders (as a result of "pinching" the image), but after enabling it, I noticed that it actually brought extra information into the frame - something like 10-20 pixels in the short borders.

What puzzles me is how the camera recorded that information because the uncorrected image already has the resolution that the sensor advertises. I speculate that MFT sensors might actually have a larger effective surface and they can collect extra information for such correction purposes.

Thanks, that was helpful. I knew that it was supposed to work that way (angle of view corresponding to corrected image), but it's good to get confirmation that the Pana 14 is actually giving the 28mm equivalent angle of view. The Sigma 19 on NEX seemed quite a bit longer, so I think it's probably longer than 28.5-equivalent on that body. Likewise our kit zooms probably start at 14.5 or 15 rather than 14, just as you said.

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It might be worth it if someone was able to check a μ43 version of the Sigma 19mm against the Panasonic 20mm to compare.